Early antibody response in mice to either infection or immunization with Salmonella typhimurium.
After immunization with either live or heat-killed Salmonella typhimurium, mice responded with an extremely rapid production of bactericidal antibody which was correlated with the appearance of immunity to a heavy challenge dose (100 ld(50)) of the virulent bacteria. Inactivation of sera with mercaptoethanol along with Sephadex fractionation indicated that the observed bactericidal activity was associated with a macroglobulin which was completely mercaptoethanol-sensitive. The unexpected finding, that a heat-killed vaccine gave excellent protection from a challenge dose which killed all unimmunized control mice, seriously challenges the theory attributing immunity against typhoid infection entirely to a cellular host factor produced only in response to a live vaccine.
D000818:Animals; D000917:Antibody Formation; D001770:Blood Bactericidal Activity; D002845:Chromatography; D006358:Hot Temperature; D007109:Immunity; D008259:Macroglobulins / Q000032:analysis; D008623:Mercaptoethanol / Q000494:pharmacology; D051379:Mice; D012481:Salmonella Infections, Animal / Q000276:immunology*; D012486:Salmonella typhimurium / Q000276:immunology*; D014436:Typhoid-Paratyphoid Vaccines / Q000494:pharmacology*
D008259:Macroglobulins; D014436:Typhoid-Paratyphoid Vaccines; D008623:Mercaptoethanol